Math Problem Statement

Compute the values of the product

1 + 1 1

1 + 1 2

1 + 1 3

1 + 1 n

for small values of n in order to conjecture a general formula for the product. Fill in the blank with your conjecture.

1 + 1 1

1 + 1 2

1 + 1 3

1 + 1 n

=

Correct: Your answer is correct. Prove your conjecture by mathematical induction. Proof (by mathematical induction): Let P(n) be the equation

1 + 1 1

1 + 1 2

1 + 1 3

1 + 1 n

=

Solution

Let's start by computing the values of the product for small values of nn.

The product in question is:

P(n)=(1+11)(1+12)(1+13)(1+1n)P(n) = \left(1 + \frac{1}{1}\right) \left(1 + \frac{1}{2}\right) \left(1 + \frac{1}{3}\right) \cdots \left(1 + \frac{1}{n}\right)

Step 1: Compute for small values of nn.

  • For n=1n = 1: P(1)=1+11=2P(1) = 1 + \frac{1}{1} = 2

  • For n=2n = 2: P(2)=(1+11)(1+12)=2×32=3P(2) = \left(1 + \frac{1}{1}\right) \left(1 + \frac{1}{2}\right) = 2 \times \frac{3}{2} = 3

  • For n=3n = 3: P(3)=(1+11)(1+12)(1+13)=2×32×43=4P(3) = \left(1 + \frac{1}{1}\right) \left(1 + \frac{1}{2}\right) \left(1 + \frac{1}{3}\right) = 2 \times \frac{3}{2} \times \frac{4}{3} = 4

  • For n=4n = 4: P(4)=(1+11)(1+12)(1+13)(1+14)=2×32×43×54=5P(4) = \left(1 + \frac{1}{1}\right) \left(1 + \frac{1}{2}\right) \left(1 + \frac{1}{3}\right) \left(1 + \frac{1}{4}\right) = 2 \times \frac{3}{2} \times \frac{4}{3} \times \frac{5}{4} = 5

  • For n=5n = 5: P(5)=(1+11)(1+12)(1+13)(1+14)(1+15)=2×32×43×54×65=6P(5) = \left(1 + \frac{1}{1}\right) \left(1 + \frac{1}{2}\right) \left(1 + \frac{1}{3}\right) \left(1 + \frac{1}{4}\right) \left(1 + \frac{1}{5}\right) = 2 \times \frac{3}{2} \times \frac{4}{3} \times \frac{5}{4} \times \frac{6}{5} = 6

From the pattern, we can conjecture that the general form of the product is:

P(n)=n+1P(n) = n + 1

Step 2: Prove by mathematical induction.

We will prove that P(n)=n+1P(n) = n + 1 by induction.

Base Case:

For n=1n = 1: P(1)=2=1+1P(1) = 2 = 1 + 1 The base case holds true.

Inductive Step:

Assume that for some k1k \geq 1, the formula holds, i.e., P(k)=k+1P(k) = k + 1 We need to prove that the formula holds for k+1k + 1, i.e., P(k+1)=(k+1)+1=k+2P(k+1) = (k+1) + 1 = k + 2

Using the inductive hypothesis: P(k+1)=P(k)×(1+1k+1)P(k+1) = P(k) \times \left(1 + \frac{1}{k+1}\right) Substitute the inductive hypothesis P(k)=k+1P(k) = k + 1: P(k+1)=(k+1)×(1+1k+1)=(k+1)×k+2k+1=k+2P(k+1) = (k + 1) \times \left(1 + \frac{1}{k+1}\right) = (k + 1) \times \frac{k+2}{k+1} = k + 2

Thus, the formula holds for k+1k + 1, completing the inductive step.

By mathematical induction, the formula P(n)=n+1P(n) = n + 1 is true for all n1n \geq 1.


Would you like more details or have any questions about this process?

Here are 5 relative questions for further exploration:

  1. How does the product change if the terms were 11n1 - \frac{1}{n} instead of 1+1n1 + \frac{1}{n}?
  2. What happens if the sum instead of the product is taken for the same terms?
  3. How can this result be generalized for non-integer values of nn?
  4. Can this formula be extended to complex numbers?
  5. What role does the harmonic series play in this type of product?

Tip: Mathematical induction is a powerful technique, often used to prove statements for sequences or recursive relations. Familiarize yourself with its base case and inductive step structure.

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Math Problem Analysis

Mathematical Concepts

Inductive reasoning
Products of series
Sequences

Formulas

P(n) = (1 + 1/1) * (1 + 1/2) * (1 + 1/3) * ... * (1 + 1/n)
Conjecture: P(n) = n + 1

Theorems

Mathematical Induction

Suitable Grade Level

Grades 10-12